[Archive!] Pure mathematics, physics, chemistry, etc.: brain-training problems not related to trade in any way - page 576

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There's enough to go around.

 
Clarity is lacking. What are the restrictions on the counting technique? Why are fingers and notches forbidden but rope knots not?
 
Mischek2: So we leave one unlit and go around and count and if it doesn't light, we light it until we get to the unlit one.

Or am I missing something?

The most important thing is to stop in time. How do you know if you've gotten to that particular unlit one? We can't make any notches.

I'm wrong, it'll just be the last one unlit when we get to the end. Seems like the right decision.

I don't fully understand it myself yet. But I didn't look for answers.

P.S. 2 MikeM: The answer is correct.

P.P.S. What if you stupidly light all the unlit, and then knock out all - now counting? Probably wrong, as surely the number of on/off attempts for each horse is limited to 1.

 
sand:
Good algorithmic problem, solved the same problem only with wagons on braingames.ru
And can I get the condition about the cars? Maybe there is more clarity there?
 
How about counting the buttons on the lantern remote instead of the horses?
There's clearly something missing from the condition. At least it doesn't make sense to me.
 
MikeM:
Can we have a condition about the wagons? Could there be more clarity there?

A lot of carriages are interlocked in a ring. The lights in the carriages are on in random order, i.e. somewhere they are on, somewhere they are off. You need to count the wagons. You can only turn on/off the lights in them.
 
sand:

Many carriages are linked together in a ring. The lights in the carriages are on in a random order, i.e. somewhere on, somewhere off. You have to count the wagons. You can only turn the lights on/off in them.
Ooh! That's better. So the merry-go-round is spinning and we're standing behind a fence. Now we just have to figure out how we can control the lanterns.
 
MikeM:
Uh-oh! That's better. So the merry-go-round is spinning and we're standing outside the fence. It remains to be seen how we can control the lanterns.


And the merry-go-round and the cars are stationary. You don't have to stand around and count. You have to walk around the carriages inside, and in the carousel from one horse to the next. The number of light switches is unlimited.
 
sand: Both the merry-go-round and the cars are stationary. You're not supposed to stand around and count. You should walk around the carriages inside, and in the carousel from one horse to the next. The number of light switches is unlimited.

How is that not a solution?

Mischek2: so we leave one unlit and go around the circle counting and if it's not lit - light up until we get to the unlit one
P.S. Got it now. No way to find out whether the next light is already last or not. In the braingames.ru task, the number of cars can be very high.
 
Mathemat:

Why isn't this the solution?


How do you leave one unlit? You can't see the whole picture.
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